This invention relates to model aircraft construction jigs.
An object of the invention is to provide a versatile improved form of construction jig which can facilitate the building of at least fuselage and tail unit assemblies of model aircraft using conventional adhesively-bonded plywood and/or balsa wood construction techniques, and the invention can be especially useful for providing construction jigs for building flying models of aircraft, such as radio controlled models, in which a high degree of precision is required in assembly and alignment, particularly in respect of the fuselage and tail unit.
In conventional techniques of model aircraft construction, the fuselage is built up in balsa or plywood from a pair of elongate side walls assembled in spaced-apart relationship and interconnected to form a framework by a plurality of spacing formers, usually of small laminate shape, which extend transversely between the side wall pieces in vertical planes perpendicular to the longitudinal axis of the fuselage and which are spaced apart at intervals along the length. The formers are glued or bonded by adhesive along their edges to the inwardly-presented faces of the side wall pieces and, by their individual dimensions and relative dispositions, they collectively determine the overall profile of the fuselage framework which is subsequently covered with appropriate sheeting. After building the fuselage framework, the tail unit, comprising tail plane portions with elevators and, usually, a tail fin portion with rudder, is built on, after which the wings, separately prefabricated, are fitted.
The components are usually made and assembled with reference to a detailed full-scale plan or drawing, and in carrying out the above building operations and in bonding the components together it is important, especially for obtaining proper flying characteristics, to ensure that the fuselage has a straight center line or longitudinal axis, and is not twisted, with all the laminate formers perpendicular to said center line or longitudinal axis, while the tail unit must be properly aligned and symmetrically positioned relative to the fuselage center line with tail plane and tail fin portions in correct relative angular orientation. Also, the wings must of course be carefully fitted and located so that finally the whole assembled and bonded structure is correctly lined up.